oe basel



rennin! June 192?.

GIOVANNI TAGLIAHI, GI? BABEL, SWITZERLAND, ABBIGHGR, BY HESHE A8816 2 14:

To CHEMICAL WORKS, FORHEELY EAHDCIZ,

0Y BASED, SWITZEBLAKD, ,5. rom- Ho Drawing. Application filed Jane 28,1925, Serial Ho. 40,452, and in Germany July 3, 12%

lhe present invention relates to improvements in a process of treatingcotton or other cellulose-fibers in order to render them indifferent to}substantive dyestuffs.

It is known that vegetable fibers carr'be rendered indifferent tosubstantive dyestuffs by treating them after an'alkallzation wlth carbonacid chlorides, preferably in the presence of indifferent organicsolvents. This recess has, however, the disadvantage of being relativelyexpensive owing to the acid chlorides WlllCh have to be used, and,moreover, the cellulose compound thus obtained not resistant to variousagents used in the treatment of textile fibers, especially to alkaliesand to high temperatures.

Further, a process has been (.lGZCllbOd for rendering uncoloredcellulose fibers, or such which have been dyed in the vat, indifi'erentto substantive dyestuffs, by alkaiizing them and treating themafterwards with sulphonic chlorides of the aromatic series, wherebythese. aromatic sulphomc chlorides are preferably used in the presenceof in- This process has essential advantages compared with theabove-mentioned process, which consists in that cheap esterifying agentscan bccmployed, and that. the cellulose compounds obtained by means ofthe aromatic -sulphonic chlorides are more stable against alkalies andother agents and against. high temperatures than those obtained bymeansof aromatic carbonic chlorides.

' In further improvement of this last mentioned process I have foundthat cellulose fibers, loose or in the shape of threads, or' as Wovenfabric, preliminarily dyed with substantivc dyestuffs, can be renderedindifferent against other substantive dyestuffs.

Ewample.

Cotton yarn, dyed with a substantive dyestuff is alkalized by treatin itfor a certain time in a 14%. alcoholic so ution of caustic soda. Thethus treated yarn is then withdrawn and hydroextracte'd to remove anexcess of lye.

l k of the alkalizge-d yarn-is then imrnersc in a resistant vessel,containing 15 litres of e 20% solution of; paratoluene sulphonicchloride in tetrachloride of carbon. After a short time the recictiontakes placeand the temperature without'the boiling point or the liquidbeing reached. It is important that the yarn is alwa s wholly immersed.Thereupon the 12 110 e is allowed to cool down {or several hours, and isthen heated again until the boiling point of the liquid is nearlyreached. The yarn is then removed, hydroeztracted and afterwards seepedseveral times in a bath at about 60 C. until the smell of carbon tetrachloride and paratoluene sulphonic chloride has almost completelydisappeared. The fibres are then hydroextractcd and dried. The thusobtained fibres resist all the usual agents of the textile industry,such as acids, alkalies and reducing agents.

To alkalize the dyed vegetable fibres, caustic potash may be usedinstead of causticsoda. Tctraehloride of carbon may be replaced by anyother indifferent organic solvent, such as the halogenizegl hydrocarbonsof the aliphatic series, further hydrocarbons of the petroleum seriesand )articularly. benzol and its hornolo ues. aratoluenc sulphonicchloride may e replaced as. esterifying agent by anotheraromatic'sulphonic chloride, for instance benzene sulphonic chloride,ortho toluene sulphonic chloride, xylene sulphonic 'chloride andnaphthalene sulphonic chlorides, as well as their halogen derivatives.

Iclaim I l. A process of rendering cellulose fibres, preliminaril' dyedwith substantive dyestuffs, indi erent to substantive dyestuffs,

which comprises alkalizing the dyedfibresand treating them with aromaticsulphonic chlorides. 2. A process of rendering cellulose fibres,

preliminarily dyed with substantive dyestulls, indi'ilerent tosubstantive dyestulfs, which comprises alkalizing the dyed fibres andtreating them with phonic chloride.

In testimony whereof, I have signed my name to this specification.

GIOVANNI ra ium.

95. para toluene sul

